Vehicle not starting

Hello.

I have a Nissan Serena. This car has failed on me at the gas station when I was refilling the fuel. It was driving fine, and when I switched it off, it did restart, but couldn't rev past 2000 rpm.

I scanned it and it gave the code of Mass air flow meter which I changed with another one and it didn't change a thing.
I then left and tried it the next day, there was no code, and the vehicle only cranked, but this time the car wouldn't start.

*I then checked and lifted the whole injector rail, and cranked, and all injectors sprayed on their on time.
*I checked the spark plugs, and it plug sparked and that proves the coils and spark plugs are fine.
*I redid the timing marks as well
*The fuel pressure is good, and I even changed the fuel filter and pump.

All the above has been done, and the vehicle still can't start.

Please advise